The present invention is directed in general toward method and apparatus for use with personal computers and, more particularly, toward method and apparatus for locking out selected ones of the keys of a personal computer keyboard.
Personal computers (PCs) have become more and more popular as their availability, cost and dependability become more satisfactory. With the widespread use of personal computers several manufacturers are attempting to provide a univeral device which can be adapted to a variety of uses. To do so, however, it is necessary to provide functions in the universal device which are not required for many applications. This results in several keys being present on the personal computer keyboard which are not needed for the application for which the device is currently being used. It is, however, undesirable to provide keys on a keyboard when the function provided by the key is not being used. This results in unnecessary time being consumed correcting errors when these keys are accidentally pressed.
Some prior art methods for locking out the keys of a keyboard require a plastic insert to be placed in the keyboard to prevent the locked out key from making contact with the contact pad of the keyboard. In this manner, position indicative signals (a plurality of signals whose combination indicate the position of the pressed key) are not transmitted to the personal computer when the locked out key is pressed. However, using this apparatus and method assembly and disassembly of the keyboard is necessary to lock out keys thereby decreasing the useful life of the keyboard. Also, it is difficult and time consuming to lock out a particular key.
Other methods for locking out keys provide a plastic cap or similar device to be placed over the key such that the key cannot be pressed. The plastic caps are, however, unsightly. Further, the caps tend to fall off of the keyboard and are therefore unreliable.
Still other methods for locking out certain combinations of keys, e.g., parental lockout systems on television sets, typically provide a memory for storing the locked out combination. The memory is addressed after each key combination is entered to determine whether the entered combination is locked out. These systems, however, are slow in operation. Further, these systems rely upon a enter key being pressed to acknowledge that a desired combination has been entered. Lastly, it is noted with these systems that keys are not locked out but key combinations are locked out, i.e., the keys are still recognized by the processor.
It is desirable, therefore, to provide method and apparatus for locking out the keys of a personal computer keyboard when their function is not needed. It is also desirable to provide such method and apparatus which is reliable and allows for quick and easy locking or unlocking of the keys of a keyboard.